This’ll get posted to the Truck Norris thread, as well, but I thought it deserved its own topic.
In the event that your bulkhead needs to be above the bottom edge of the tank, you can still get to the bottom with a down-tube installed on the reverse side of the bulkhead
I used PVC because it was readily available, could be glued for a vacuum tight seal, and doesn’t require any additional hardware (hose clamp, etc.) inside the tank.
1” PVC street elbow with glue fitting on female side, pipe thread on the male side.